<pre></code>
Macros are ruby sripts
They can be short oneliners (copy,copy-format)
 or complete programs

They run in the enviroment as self == the TableFrame (main win)
@curTable is the RTable for the shown grid
Fixnum instances have the method table()
so 0.table => the RTable for current grid

They must define a block of 

=begin
DESCRIBE:
[description here]
:DESCRIBE
:OPTIONS
[explain options here]
:OPTIONS
:EXAMPLE
[an example of options usage]
:EXAMPLE...
=end
</code></pre>
